In the injection molding industry, the monitoring and control of the injection molding process is typically critical to the proper molding of the desired part, for example, a part free of voids and defects. It is recognized in the art, that one way of controlling the quality of the part produced is to monitor and control the pressure and flow rate of the injected molding medium, for example, fluid wax or plastic, or molten metal. One recognized method for monitoring the pressure of the molding medium is to monitor the pressure directly by introducing a pressure sensing device in the molding medium injection conduit. This method of detecting molding medium pressure is disclosed in U.S. Pat. No. 5,316,707 and is typical of similar practices in the art. One recognized method for monitoring the flow rate of the molding medium is to monitor the deflection of the hydraulic piston used to displace the molding medium injection piston and, from the geometries of the respective piston bores, calculating the flow rate of molding medium to the mold. This method of determining mold medium flow rate is also disclosed in U.S. Pat. No. 5,316,707 and is also typical of similar practices in the art.
However, these prior art methods of monitoring the operation of an injection molding machine have disadvantages. For example, such methods must typically be dedicated to a specific machine and are typically not transferable to other machines, for example, other local or remote injection molding machines. In addition, these prior art methods require the interested party to have some form of access to the molding injection passage to insert a pressure detecting device to detect injection pressure and access to the injection piston to physically monitor its deflection. These disadvantages, among others, are overcome by aspects of the present invention.